1. Field
The following description relates to a driving method of a current compensation circuit. The following description also relates to the current compensation circuit and light apparatus having such a current compensation circuit so as to accurately control an average driving current regardless of changes of an input voltage and an output voltage.
2. Description of Related Art
An LED (Light Emitting Diode) light apparatus may be driven through a switching converter method and a switching converter may be classified according to a Buck-type, a Boost-type and a Buck-Boost-type. A Buck-type converter is a voltage step down and current step up converter. A Boost-type converter is a DC-to-DC power converter with an output voltage greater than its input voltage. A Buck-Boost type converter is a type of DC-to-DC converter that has an output voltage magnitude that is either greater or less than the input voltage magnitude. Previously, a switching converter of the Boost-type was used the most, but recently the Buck-type is used more often for cost reduction of an integrated circuit (IC). A type of a switching converter may be classified according to a ratio of an input voltage and an output voltage and may include a Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) in order to employ an average inductor current mode method.
An LED light apparatus may be driven by a high efficiency light apparatus driving circuit including a MOSFET. An ideal MOSFET immediately turns on when a driving current driving an LED module reaches a zero value. However, a real MOSFET may generate a delay between a point in which a driving current reaches a zero value and an actual turn-on point. Therefore, when an LED light apparatus is driven by a real MOSFET, a minimum value of a driving current may correspond to a negative value and an average driving current may decrease compared with an ideal MOSFET.